Abstract: Economic valuation is basically aimed to help decision makers to estimate economic efficiency of various utilization activities which might be due to the ecosystem in coastal area like seagrass ecosystem and other marine ecosystems, including small islands. Information about the economic value of seagrass ecosystem services is very limited, especially in Eastern Indonesia; therefore, a study which aims to evaluate seagrass ecosystem services in Kotania Bay Marine Nature Tourism Park, Western Seram District, Maluku Province, needs to be done. Seagrass meadows have become a popular topic due to its high productivity in coastal areas and also because of its substantial ability to store carbon. Economic valuation of seagrass ecosystem services in this conservation area covers two types of ecosystem services: Provisioning service (approached by its role as a primary productivity source through consumer surplus) and regulation services (approached by seagrass’s ability in storing carbon through the replacement cost method). Estimation of the economic value of seagrass ecosystem services in the waters of Kotania Bay as provisioning service and regulation service are IDR 21,014,755,749. The results are important input for the decision makers in the region in order to maintain the sustainability of the seagrass ecosystem found in Kotania Bay Marine Nature Tourism Park.